Lungs

• Humans have two lungs in the thorax (with the heart) protected by the ribs; air is breathed in and enters the lungs via the glottis, which is opened when the epiglottis is raised
• Nose adaptations: Made of epithelial cells covered in cilia, has many capillaries (to warm air, increase diffusion), hairs to trap dust/particles (also mucus for the same purpose)
• Air passes past the larynx (voice box), down the trachea into the right or left lung via the bronchus; these lead into a network of smaller tubes, bronchioles, the narrowest of which eventually end in a collection of air sacs (alveoli)
• Respiratory muscles are responsible for moving the rib cage in ventilation: the diaphragm, a muscle sheet below the lungs, separates the thorax and abdomen, intercostal muscles stretch between adjacent ribs to form the thoracic sides
• Airway Features: Branching pattern, cartilage, smooth muscle, and complex epithelium with goblet cells, mucus glands and ciliated epithelial cells; airways become progressively simpler with fewer tissue layers, the further in the lung you go
• Advantages of a branching structure: Minimum distance from nose to alveolus, as tubes narrow, there are more of them, the total cross-section area of passages is always high and reduced resistance to airflow
• Human Thorax

  A) Epiglottis

  B) Glottis

  C) Oesphagus

  D) Intercostal Muscles

  E) Cutend of Rib

  F) Heart

  G) Lung

  H) Diaphragm

  I) Pleural Cavity

  J) Pleural Membranes

  K) Bronchus

  L) Trachea

  M) Larynx

  N) Nasal Cavity

  
• Ventalation Table

  A) contract

  B) up and out

  C) Relax

  D) up and out

  E) contract

  F) flatten

  G) move down

  H) increases

  I) into

  J) air pressure

  K) Inflate

  L) Relax

  M) in

  N) contract

  O) forced

  P) gravity

  Q) down and in

  R) Relax

  S) domes

  T) decreases

  U) out

  V) air

  W) pressure

  X) deflate

  
• Summary of the alveoli and surrounding tissues for efficient exchange of oxygen and carbon dioxide in mammals

  A) many

  B) Surface Area

  C) higher

  D) diffusion distance

  E) single-layer of squamous epithelial cells

  F) increase

  G) capillaries

  H) diffusion

  I) gradients of CO_2 and O_2

  J) endothelium

  K) short

  L) permeable

  M) nitrogen

  N) intercostal

  O) Diaphragm

  P) steep diffusion gradient

  Q) narrow

  R) erythrocytes

  S) closer

  T) slower

  U) low

  V) bursting

  W) surfactant

  X) water

  Y) osmosis

  Z) cohesive

  [) collapse

  \) stretch

  ]) recoil

  
• Distribution and functions of tissues and cells in the lungs

  A) skeletal

  B) c

  C) structural

  D) c

  E) restricting

  F) colomnar

  G) hair-like

  H) mitochondria

  I) ATP

  J) mucus

  K) synchronised

  L) pathogens

  M) sticky mucus

  N) contracts

  O) constricts

  P) harmful

  Q) connective

  R) connective

  S) recoil

  T) widen

  U) deformed